1. Field of the Invention
The present invention relates to a windshield wiper switch, and more particularly to a windshield wiper switch which permits switching for wiper operations as well as spouting of windshield washer liquid.
2. Description of the Related Art
An automobile is equipped with a windshield wiper to wipe waterdrops and to remove dirt from the windshield when it is raining.
Generally, the windshield wiper is so constructed as to perform switching for a plurality of wiping operations as well as spouting of windshield washer liquid.
FIG. 7 is a perspective view showing a conventional windshield wiper switch. A rotary switch 2 and a push switch 3 are arranged in a sleeve 1. The rotation of a knob 4, rotatably attached to the sleeve 1, in directions indicated by an arrow .theta. makes it possible for the rotary switch 2 to be turned to either of the following positions: a HI (high speed) position, an LO (low speed) position, an OFF (halt) position and a MIST position (operative while the knob 4 is in operation). An adjusting system maintains these positions.
Further, the press of the push button 5, associated with a push switch 3, in the direction indicated by an arrow Y turns a connection ON, thereby allowing windshield washer liquid to spout.
According to a windshield wiper switch as constructed above, the switching of operations for the rotary switch 2 makes it possible for the windshield wiper to reciprocate at a high or low rate for removing waterdrops. The windshield wiper also reciprocates to remove waterdrops while the knob 4 is in operation. In addition, windshield washer liquid is spouted by pushing the push button 5 during the above reciprocating motion to wash the windshield.
In most cases, while the windshield is being washed with spouted windshield washer liquid, the windshield wiper needs to be operating.
Hence, the type of windshield wiper switch as described above is so constructed that when a driver pushes the push button 5 to spout windshield washer liquid while the rotary switch 2 remains in the OFF position, a cam system 19 interposed between the rotary switch 2 and the push switch 3 shifts the rotary switch 2 to the LO position. In other words, the windshield wiper switch is so designed that even when the driver pushes the push button 5 without first shifting the rotary switch 2 to the LO position, the windshield wiper is interlocked by the cam system 19 with the push button 5 to shift to a low rate for spouting windshield washer liquid.
According to the conventional art, the push button 5 needs to be pushed strongly, since the rotary switch 2 is actuated with the aid of the cam system 19. If a driver, however, pushes the push button 5 too strongly, then the rotary switch 2 may be switched over to the HI position, without stopping in the LO position. This phenomenon is undesirable in terms of windshield washing.